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Discussion Starter · #1 ·
I have a 2008 Mazda 3 i sedan, and I just recently added HID headlights and LEDs to the interior, license plate and reverse lights. I was talking to a guy the other day, and he said that I should replace my alternator as soon as I can. He said it is because I am pulling so much extra power than before, and I should have an alternator that replaces the energy... I'm a little confused and any information would be very helpful.

CJ
 

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Unless you have a power draining sound system you do not need a stronger Alternator.

HIDS use less power and LEDS draw very little power.

You should be fine.

Are you having any electrical issues ??
 

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Discussion Starter · #3 ·
I just have the stock sound system. No power issues except sometimes I haven noticed that the left headlight will flicker a few times right when I turn them on. But once they "heat up" everything is fine.
 

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The power draw of the LEDs is negligible, esp. since they're just replacements and not add ons. Like Troy said HIDs draw less power than halogens (except on startup). Is this "guy" a mechanic? Did he offer you a really good deal on replacing an alternator? Flat out you don't need one. Most of the people who have big systems just replace their batteries and have no problems.... honestly I think the only person I've seen who did replace theirs was jeba, and he did stereo competition.
 

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Discussion Starter · #7 ·
Actually, I have no idea who this guy is. He was just talking to some other guy at our table while I was playing Online Poker and we just started talking about cars. I think he was a professional tint installer or something. From the sounds of it, I don't think I need a new one. Thanks for your guys input, much appreciated. :cheers:

CJ
 

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Just to let everyone know.... That the upgraded alternators for this car are into the $600 -$800 range.

You can't just have it upgraded either cuz of our electronic regulator. Even people who actually need the alternator won't be getting it cuz of the price!

If it was $200 -300 I would of got one my self. You obviously don't need one -- but anyone with a decent sound system can benefit from a better alternator.
 

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has anybody actually replaced alternator, i'm on the same dilemma right now, with my 04 hb, i have hid lights,hid fog lights, a/m piaa fog lights and 600w amp/subwoofer package, and i was wondering if someone has replaced it before and what was the outcome??
thanks.
 

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[quote author=elsosa2007 link=topic=136851.msg3239755#msg3239755 date=1248212793]
has anybody actually replaced alternator, i'm on the same dilemma right now, with my 04 hb, i have hid lights,hid fog lights, a/m piaa fog lights and 600w amp/subwoofer package, and i was wondering if someone has replaced it before and what was the outcome??
thanks.
[/quote]

As I posted above the only member I know of who's replaced the alternator was jeba and he did stereo competition and was a professional installer.
 

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im running hids on my hi and low beams, four 150watt MINIMUM power infinity interiors, two 70 watt MIN. Memphis tweeds, and a 500Wat MIN sub. All powered at their minimum requirements. AKA powered right, f you look at what i call the retard specs im running somewhere around 2000wats MAX. Cranked my headlights don't even flicker, and all i have is a small cap and a optima red top. Thee a local member on here that can attest to that.
 

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[quote author=3driverPA link=topic=136851.msg3239921#msg3239921 date=1248220717]
im running hids on my hi and low beams, four 150watt MINIMUM power infinity interiors, two 70 watt MIN. Memphis tweeds, and a 500Wat MIN sub. All powered at their minimum requirements.[/quote]

Minimum requirements? What does that mean?
 

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exactly what it says, the minimum amount of power required to power the speakers. If you have a sub that requires a minimum of say 600watts, but your amp only pushes a min of 100, you'll notice your headlights will dim like crazy. The amp pulls WAY more power from the battery to power the subs needs.

here the technical definition of min power or RMS.


The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts.
 

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[quote author=3driverPA link=topic=136851.msg3240072#msg3240072 date=1248224762]
exactly what it says, the minimum amount of power required to power the speakers. If you have a sub that requires a minimum of say 600watts, but your amp only pushes a min of 100, you'll notice your headlights will dim like crazy. The amp pulls WAY more power from the battery to power the subs needs.

here the technical definition of min power or RMS.


The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts.[/quote]

RMS power is actually the root mean square power. You could use it to describe any level of power. It's just the way you calculate the average output of any AC current. A proper amplifier rating will give RMS output power for a specified frequency range, with a specified distortion level, and at a specified input voltage. That rating is not the minimum, it is the maximum continuous clean power that an amp is capable of producing, with continuous referring to any time period longer than a small fraction of a second. I personally refer to any rating that doesn't provide all that information as an ILS - If Lightning Strikes - rating. Retard specs isn't a bad term for that either!

Unless you have everything at full volume, your amp isn't using anywhere near that much power. Like an electric motor, it only draws as much power as it needs, no matter what it's capable of. If you have an amp with a rating of 600W RMS at 20Hz to 20kHz with 1.0% THD at 14.4V powering four speakers, and the four speakers are at a volume where they're only using 5W each (maximum clean power for a typical head unit!), the amp is probably using somewhere between 20W and 40W, depending how efficient it is. It's capable of a lot more, but it isn't using it in that situation. The minimum power requirement for a speaker to function at very low volumes isn’t much – usually fractions of a watt - though I suppose speaker manufacturers may give recommendations for what level of clean power is necessary to take full advantage of a speaker's capabilities.

Whether your headlights flicker is determined by capacitance, not just how much power the amp can put out. A better amp will likely have more capacitance built in to reduce the effects of surges on the battery voltage, but if a smaller amp causes headlight flicker it’s not actually due to inadequate power, it’s due to inadequate capacitance. If two stereo systems have the same total capacitance (on the power input side), the one putting out more power will be the one that causes the most headlight flicker.

Of course, if your stereo can put out 1200W it would be drawing even more than that. So it does sound like our alternators put out plenty of electrical power for anything but the most extreme mods. I assume by "small cap" you're running a 0.5F cap?
 

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You missed something Root Mean Square is for AC current, cars are DC.....

And my caps a full 5farrad, anything smaller then that is really just a show piece unless you have a tiny amp...
 

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[quote author=3driverPA link=topic=136851.msg3242998#msg3242998 date=1248370449]
You missed something Root Mean Square is for AC current, cars are DC.....

And my caps a full 5farrad, anything smaller then that is really just a show piece unless you have a tiny amp...
[/quote]

The input is DC, but the output to the speakers is AC.

Wow, 5F is a big cap compared to what I used to see back when I was a stereo junkie. No wonder your lights don't flicker!
 

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honestly they didn't flicker before i got it.  I just got it because the systems trashed my stock battery in about a week. I have friends who are reallly into audio, they all have like 20 farad caps, basically another battery in their cars. But in my case Im running a lot of power but no too much to over power the car charging system. I did a test and use can do it too. A friend of mine had a little 100watt rms amp laying around so i hooked it up to my type-r sub rated at 500watts rms. When i hooked it up my lights flickered like hell, versus when i used my 400watt class D amp. The sub couldn't get the power it needed from the amp so it took it from the next source, the charging systems, causing everything to go dim or flicker.
 

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[quote author=3driverPA link=topic=136851.msg3244720#msg3244720 date=1248446478]
honestly they didn't flicker before i got it. I just got it because the systems trashed my stock battery in about a week. I have friends who are reallly into audio, they all have like 20 farad caps, basically another battery in their cars. But in my case Im running a lot of power but no too much to over power the car charging system. I did a test and use can do it too. A friend of mine had a little 100watt rms amp laying around so i hooked it up to my type-r sub rated at 500watts rms. When i hooked it up my lights flickered like hell, versus when i used my 400watt class D amp. The sub couldn't get the power it needed from the amp so it took it from the next source, the charging systems, causing everything to go dim or flicker.
[/quote]

The sub gets all its power directly from the amp. If it's flickering, the amplifier is just pulling too much instantaneous current from the electrical system whenever there's a big sub hit, and the system doesn't have the capacitance to keep voltage steady. A class D amp is great for subs as it is much more efficient than a class AB amp, so it's drawing a lot less power from the system to produce the same volume as the little amp. The other thing is, if you took the covers off both amps, you'd see much larger capacitors built into the better amp. It really doesn't take much of a capacitor to help keep the voltage steady enough to avoid light flickering. It seems that a larger cap isn't terribly expensive these days, so it was probably a good idea to keep your battery and alternator healthy with that 5F cap.

I've been running my Alpine R12 off a 200W RMS Alpine V12 amp with no external capacitor for the last ten years with no flicker or electrical problems (previous car was an '87 Grand Am). I don't crank it that often anymore, but I used to. It's been a good combo.
 

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[quote author=3driverPA link=topic=136851.msg3240072#msg3240072 date=1248224762]
exactly what it says, the minimum amount of power required to power the speakers. If you have a sub that requires a minimum of say 600watts, but your amp only pushes a min of 100, you'll notice your headlights will dim like crazy. The amp pulls WAY more power from the battery to power the subs needs.

[/quote]

i said that earlier i was just trying to speak laymen, didn't know that about class d amps though. Learn something new everyday
 

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[quote author=3driverPA link=topic=136851.msg3246019#msg3246019 date=1248496450]
i said that earlier i was just trying to speak laymen, didn't know that about class d amps though. Learn something new everyday
[/quote]

Yeah, I just wanted to clear up some terminology and I ended up taking it further than I expected. Us engineers tend to go overboard on that stuff!
 
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